Field of the Invention
The present invention relates to a method of predicting a formed body density and a method of manufacturing a ceramic fired body.
Description of the Related Art
Conventionally, a ceramic fired body is configured as, for example, a honeycomb structure having a honeycomb shape, and is used for'a wide range of applications such as a catalyst carrier for purifying automobile exhaust gas, a diesel particulate removal filter, or a heat storage body for a combustion device. The ceramic fired body is manufactured in such a manner that a forming raw material is extruded to produce a ceramic formed body, which then undergoes a firing step of firing the formed body at a high temperature. A honeycomb structure, which is one of the ceramic fired bodies, has polygonal lattice-like partition walls that define a plurality of cells becoming through channels for fluid and extending from one end face to the other end face.
A forming step of extruding a ceramic formed body into a desired shape is performed using an extruder, in which an extrusion die (die) having a desired shape is attached to an extrusion port. In the forming step, a forming raw material is extruded from the extrusion die at a predetermined extrusion pressure and a predetermined extrusion speed in a state where the extrusion direction is made to coincide with the horizontal direction.
Various kinds of ceramic raw materials, pore formers, binders and the like are used as the forming raw material, and they are mainly powder or in a powdery form. Therefore, in order to allow extrusion from the extruder, liquid such as water and/or surfactant is added in a mixing step of mixing the ceramic raw material and the like. In the mixing step, by using a batch type mixing apparatus (batch mixer), first, two or more kinds of aggregate particle raw materials such as the above-mentioned ceramic raw material, weighed based on a predetermined mixing ratio, are subjected to dry mixing (first mixing), and further subjected to wet mixing (second mixing) in which liquid (water) is added, thereby obtaining a wet mixture (forming compound) (see Patent Document 1). Thereafter, through a kneading step of kneading the wet mixture (forming mixture) subjected to the wet mixing, a forming raw material adjusted to have a predetermined viscosity suitable for extrusion is extruded from the extruder.                [Patent Document 1] WO 2005/018893 A        